# Audio Calc LUFS Math

> Audio Calc LUFS Math is a paid API for AI agents from audio-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-30).

Calculates loudness gain adjustments to hit a LUFS target or streaming platform standard, predicts true peak after gain, and combines segment loudness values.

## Facts

- Endpoint: GET https://audio-calc.x402tookit.com/lufs-math?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/audio-calc-lufs-math-636c0866
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZsvSU8CmPJBCUAQ6S3Ish

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability audio-calc-lufs-math-636c0866
```

Example prompt: My track measured -18 LUFS and I want to normalize it for Spotify — how much gain do I need, and will the true peak stay under -1 dBTP if my current true peak is -4 dBTP?

## When to prefer this

Use this endpoint when you need precise loudness mathematics for audio normalization workflows — especially when targeting named streaming platforms (Spotify, YouTube, Apple Music, etc.) or broadcast standards (EBU R128, ATSC A/85), when predicting whether a gain adjustment will cause true peak clipping, or when combining multiple audio segment loudness values into a single integrated LUFS figure. Prefer over manual calculation or general audio tools when you need instant, deterministic results with platform-specific targets built in.

## Known failure modes

- Missing required 'lufs' parameter when computing gain results in an error or degraded response
- Invalid or unrecognized platform name for 'target' returns an error or falls back to numeric
- Malformed 'segments' string format causes parsing failure
- True peak values provided as positive numbers instead of negative dBTP may produce unexpected results
- Missing segment data when combination mode is implied

## How this service works

Loudness maths: gain to a LUFS target or platform, resulting true peak vs ceiling, or combining segment loudness.

## Output

Returns a JSON object with the calculated gain in dB and linear scale, the predicted new true peak in dBTP, peak headroom remaining, whether limiting is needed, the target LUFS (and source/platform name if a named target was used), the combined LUFS if segments were provided, a human-readable summary and verdict, plus any caveats or platform targets table.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "lufs": {
       "type": "number",
       "description": "Measured integrated loudness in LUFS (negative), for example -9.5"
      },
      "target": {
       "type": "string",
       "description": "Target LUFS or a name: spotify, youtube, apple-music, amazon-music, tidal, podcast, ebu-r128, atsc-a85, arib-tr-b32"
      },
      "segments": {
       "type": "string",
       "description": "To combine: lufs:seconds pairs, for example -20:30,-10:30"
      },
      "ceilingDbtp": {
       "type": "number",
       "description": "True-peak ceiling in dBTP (default -1)"
      },
      "truePeakDbtp": {
       "type": "number",
       "description": "Measured true peak in dBTP, to predict the peak after the gain"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "mode": {
       "type": [
        "null",
        "string"
       ]
      },
      "gainDb": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "platform": {
       "type": [
        "null",
        "string"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "gainLinear": {
       "type": [
        "null",
        "number"
       ]
      },
      "notChecked": {
       "type": [
        "ar
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/audio-calc-lufs-math-636c0866/health.json
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